This guide contains materials about and from the Educator Externship Program for School-to-Career Partnerships in Western Colorado, which was organized to give educators an opportunity to experience firsthand the changes occurring in various business sectors. The guide begins with a discussion of the elements and benefits of externships, during which participating educators spend a period of time at a worksite so that they can explore and learn about the workplace and community at large. The following aspects of designing and implementing externships are discussed: initial research; design (desired outcomes, structure, logistics); material development; recruitment; scheduling; evaluation; and product development. Presented next are the syllabus and agenda from the externship held in summer 1998, a 2-credit hour program during which educators attended classroom presentations and a practicum with local businesses and industry. The following items are also included: flyer and registration form; letters to educators and employers; discussions of the role of employers in externship programs, career interest pathways, the Secretary's Commission for Achieving Necessary Skills competencies and Colorado Workplace Competencies; lesson plan template; lesson matrix; educator and employer evaluation forms and results; and list (including source addresses) of four guides to developing teacher externship programs. (MN)